| File: 01_initial_periodontal_therapy_data.csv | | | | | | | | |
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| Variable | Type | Range | Categories | Unit | Missing values | Derived | Source | Description |
| pat_id | Integer | 7 to 4517 | | | None | No | Patient records | Patient identifier, unique within the dataset and not linkable to clinical records |
| gender | Categorical | | female, male | | None | No | Patient records | Sex of the patient as recorded at the initial examination |
| age_2000 | Integer | 18 to 84 | | years | None | No | Patient records | Age the patient had in the year 2000 |
| age_baseline | Integer | 20 to 84 | | years | None | No | Patient records | Age at the initial examination, before active periodontal therapy |
| med_history | Categorical | | antibiotic_prophylaxis, anticoagulants, antidepressants, antiepileptic_drugs, healthy, infectious_disease, miscellaneous | | 5 | No | Patient records | Relevant medical history at the initial examination. Blank where no information was recorded |
| smoking | Categorical | | former smoker, non-smoker, smoker | | None | No | Patient records | Self-reported cigarette smoking status at the initial examination |
| diagnosis | Categorical | 1 to 3 | | | None | Partly | Study records / derived | Severity of periodontal disease at the initial examination: 1 = no or mild (no site exceeding 4 mm), 2 = moderate, 3 = advanced (at least ten sites of 6 mm or more) |
| diagnosis_source | Categorical | | derived, recorded | | None | No | Study records / derived | Provenance of diagnosis: recorded = taken from the original study records; derived = reconstructed from the baseline site counts using the published definition |
| n_teeth_baseline | Integer | 4 to 32 | | count | None | No | Clinical examination | Number of teeth present at the initial examination |
| n_4mm_baseline | Integer | 0 to 101 | | count | None | No | Clinical examination | Sites with a probing depth of exactly 4 mm at the initial examination |
| n_5mm_baseline | Integer | 0 to 68 | | count | None | No | Clinical examination | Sites with a probing depth of exactly 5 mm at the initial examination |
| n_6mm_baseline | Integer | 0 to 54 | | count | None | No | Clinical examination | Sites with a probing depth of exactly 6 mm at the initial examination |
| n_from7mm_baseline | Integer | 0 to 73 | | count | None | No | Clinical examination | Sites with a probing depth of 7 mm or more at the initial examination. Depths of 8 mm or more were not recorded separately |
| n_teeth_follow_up | Integer | 4 to 32 | | count | None | No | Clinical examination | Number of teeth present at re-evaluation after active periodontal therapy |
| n_4mm_follow_up | Integer | 0 to 86 | | count | None | No | Clinical examination | Sites with a probing depth of exactly 4 mm at re-evaluation |
| n_5mm_follow_up | Integer | 0 to 56 | | count | None | No | Clinical examination | Sites with a probing depth of exactly 5 mm at re-evaluation |
| n_6mm_follow_up | Integer | 0 to 33 | | count | None | No | Clinical examination | Sites with a probing depth of exactly 6 mm at re-evaluation |
| n_from7mm_follow_up | Integer | 0 to 28 | | count | None | No | Clinical examination | Sites with a probing depth of 7 mm or more at re-evaluation |
| apt_duration_days | Integer | 0 to 2894 | | days | None | No | Clinical examination | Duration of active periodontal therapy, from the initial examination to re-evaluation |
| n_spt_visits | Integer | 2 to 70 | | count | None | Yes | Derived | Number of supportive periodontal therapy visits recorded for the patient |
| spt_duration_years | Numeric | 0.04 to 25.68 | | years | None | Yes | Derived | Time from the first to the last recorded supportive periodontal therapy visit |
| subsample_5years | Integer | 0 to 1 | | | None | Yes | Derived | 1 for the 445 systemically healthy patients who attended supportive periodontal therapy for at least five years. Equivalent to med_history = healthy and spt_duration_years >= 5. Identifies the population of reference [2] and of the algorithm validation in reference [3] |
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| File: 02_supportive_periodontal_therapy_data.csv | | | | | | | | |
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| Variable | Type | Range | Categories | Unit | Missing values | Derived | Source | Description |
| pat_id | Integer | 7 to 4517 | | | None | No | Patient records | Patient identifier, unique within the dataset and not linkable to clinical records |
| age_at_spt | Integer | 21 to 90 | | years | None | No | Clinical examination | Age at this supportive periodontal therapy visit. A value of 90 denotes 90 years or older, aggregated in accordance with the HIPAA Safe Harbor standard |
| spt_id | Integer | 1 to 70 | | | None | No | Clinical examination | Sequential number of the supportive periodontal therapy visit within the patient. Unique per patient, not across the dataset |
| spt_year | Integer | 1985 to 2011 | | year | None | No | Clinical examination | Calendar year of the visit. No other date information is retained in this dataset |
| assigned_spt_interval_months | Integer | 3 to 12 | | months | None | No | Dental hygienist decision | Interval to the next visit as scheduled by the treating dental hygienist, based on bleeding on probing and disease severity |
| algorithm_based_interval_months | Integer | 3 to 12 | | months | 47 | Yes | Algorithm output | Interval computed from the residual probing depth profile at this visit, using the empirically determined stability thresholds of reference [3]. Takes the values 3, 4, 6 or 12 |
| true_interval_days | Integer | 0 to 4477 | | days | None | Yes | Clinical examination | Time elapsed since the preceding visit. A value of 0 marks the first visit of a patient, for which no preceding visit exists; it is not an interval of zero days |
| n_teeth_spt | Integer | 2 to 32 | | count | None | No | Clinical examination | Number of teeth present at this visit. Probing was performed at six sites per tooth, so n_teeth_spt * 6 is the denominator for all percentages |
| n_bop_pos_spt | Integer | 0 to 124 | | count | 26 | No | Clinical examination | Sites bleeding on probing at this visit; recorded at four sites per tooth |
| n_4mm_spt | Integer | 0 to 92 | | count | 47 | No | Clinical examination | Sites with a probing depth of exactly 4 mm at this visit |
| n_5mm_spt | Integer | 0 to 56 | | count | 47 | No | Clinical examination | Sites with a probing depth of exactly 5 mm at this visit |
| n_6mm_spt | Integer | 0 to 47 | | count | 47 | No | Clinical examination | Sites with a probing depth of exactly 6 mm at this visit |
| n_from7mm_spt | Integer | 0 to 33 | | count | 47 | No | Clinical examination | Sites with a probing depth of 7 mm or more at this visit. Depths of 8 mm or more were not recorded separately |
| imputed | Integer | 0 to 1 | | | None | No | Data preparation | 1 where no probing depth measurement existed for this visit in the source records and values were inserted during the original data preparation. Those values have been removed; the probing depth counts and everything derived from them are blank. The number of teeth and the bleeding on probing count were measured and are retained. The inserted values are listed in 04_data_corrections.csv |
| corrected | Integer | 0 to 1 | | | None | No | Data preparation | 1 where a probing depth measurement existed but was judged implausible and replaced during the original data preparation. The replacement is retained here, because it is the value on which the published analyses rest. Both the original and the replacement are listed in 04_data_corrections.csv |
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| File: 03_supplementary_data.csv | | | | | | | | |
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| Variable | Type | Range | Categories | Unit | Missing values | Derived | Source | Description |
| pat_id | Integer | 7 to 4517 | | | None | No | Patient records | Patient identifier, unique within the dataset and not linkable to clinical records |
| spt_id | Integer | 1 to 70 | | | None | No | Clinical examination | Sequential number of the supportive periodontal therapy visit within the patient. Unique per patient, not across the dataset |
| compliance | Numeric | 7.29262 to 185.567 | | per cent | None | Yes | Derived | Patient-level compliance with scheduled visits, as defined in reference [1]: A * 100 / E, where A is the number of attended visits and E the number of expected visits, E = sum over periods p of (m_p / i_p) with m_p the months in period p and i_p the interval assigned during that period. Values above 100 indicate that the patient attended more often than scheduled. Constant within a patient. Provided as computed for reference [1] |
| spt_period | Integer | 1 to 7 | | | None | Yes | Derived | Index of the interval period p used in the compliance calculation. A new period begins whenever the assigned interval changes. Constant within a period |
| assigned_spt_interval_months | Integer | 3 to 12 | | months | None | No | Dental hygienist decision | Interval to the next visit as scheduled by the treating dental hygienist, based on bleeding on probing and disease severity |
| n_teeth_spt | Integer | 2 to 32 | | count | None | No | Clinical examination | Number of teeth present at this visit. Probing was performed at six sites per tooth, so n_teeth_spt * 6 is the denominator for all percentages |
| n_4mm_spt | Integer | 0 to 92 | | count | 47 | No | Clinical examination | Sites with a probing depth of exactly 4 mm at this visit |
| n_5mm_spt | Integer | 0 to 56 | | count | 47 | No | Clinical examination | Sites with a probing depth of exactly 5 mm at this visit |
| n_6mm_spt | Integer | 0 to 47 | | count | 47 | No | Clinical examination | Sites with a probing depth of exactly 6 mm at this visit |
| n_from7mm_spt | Integer | 0 to 33 | | count | 47 | No | Clinical examination | Sites with a probing depth of 7 mm or more at this visit. Depths of 8 mm or more were not recorded separately |
| n_from4mm_spt | Integer | 0 to 137 | | count | 47 | Yes | Derived | Sites with a probing depth of 4 mm or more: n_4mm_spt + n_5mm_spt + n_6mm_spt + n_from7mm_spt |
| n_from5mm_spt | Integer | 0 to 100 | | count | 47 | Yes | Derived | Sites with a probing depth of 5 mm or more |
| n_from6mm_spt | Integer | 0 to 80 | | count | 47 | Yes | Derived | Sites with a probing depth of 6 mm or more |
| percent_4mm_spt | Numeric | 0 to 54.7619 | | per cent | 47 | Yes | Derived | n_4mm_spt * 100 / (n_teeth_spt * 6) |
| percent_5mm_spt | Numeric | 0 to 33.9506 | | per cent | 47 | Yes | Derived | n_5mm_spt * 100 / (n_teeth_spt * 6) |
| percent_6mm_spt | Numeric | 0 to 27.9762 | | per cent | 47 | Yes | Derived | n_6mm_spt * 100 / (n_teeth_spt * 6) |
| percent_from7mm_spt | Numeric | 0 to 19.6429 | | per cent | 47 | Yes | Derived | n_from7mm_spt * 100 / (n_teeth_spt * 6) |
| percent_from4mm_spt | Numeric | 0 to 81.5476 | | per cent | 47 | Yes | Derived | n_from4mm_spt * 100 / (n_teeth_spt * 6). This is the main exposure variable of the interval algorithm |
| percent_from5mm_spt | Numeric | 0 to 59.5238 | | per cent | 47 | Yes | Derived | n_from5mm_spt * 100 / (n_teeth_spt * 6) |
| percent_from6mm_spt | Numeric | 0 to 47.619 | | per cent | 47 | Yes | Derived | n_from6mm_spt * 100 / (n_teeth_spt * 6) |
| from4mm_3months | Integer | 3 | | months | 9793 | Yes | Algorithm output | 3 where an interval of 3 months is admissible for residual probing depths of 4 mm or more, i.e. where percent_from4mm_spt is above 20 per cent. Blank where the interval is not admissible |
| from4mm_4months | Integer | 4 | | months | 2096 | Yes | Algorithm output | 4 where an interval of 4 months is admissible for residual probing depths of 4 mm or more, i.e. where percent_from4mm_spt is 20 or less per cent. Blank where the interval is not admissible |
| from4mm_6months | Integer | 6 | | months | 2096 | Yes | Algorithm output | 6 where an interval of 6 months is admissible for residual probing depths of 4 mm or more, i.e. where percent_from4mm_spt is 20 or less per cent. Blank where the interval is not admissible |
| from4mm_12months | Integer | 12 | | months | 6190 | Yes | Algorithm output | 12 where an interval of 12 months is admissible for residual probing depths of 4 mm or more, i.e. where percent_from4mm_spt is 10 or less per cent. Blank where the interval is not admissible |
| from5mm_3months | Integer | 3 | | months | 10529 | Yes | Algorithm output | 3 where an interval of 3 months is admissible for residual probing depths of 5 mm or more, i.e. where percent_from5mm_spt is above 10 per cent. Blank where the interval is not admissible |
| from5mm_4months | Integer | 4 | | months | 1360 | Yes | Algorithm output | 4 where an interval of 4 months is admissible for residual probing depths of 5 mm or more, i.e. where percent_from5mm_spt is 10 or less per cent. Blank where the interval is not admissible |
| from5mm_6months | Integer | 6 | | months | 2977 | Yes | Algorithm output | 6 where an interval of 6 months is admissible for residual probing depths of 5 mm or more, i.e. where percent_from5mm_spt is 6 or less per cent. Blank where the interval is not admissible |
| from5mm_12months | Integer | 12 | | months | 6439 | Yes | Algorithm output | 12 where an interval of 12 months is admissible for residual probing depths of 5 mm or more, i.e. where percent_from5mm_spt is 2 or less per cent. Blank where the interval is not admissible |
| from6mm_3months | Integer | 3 | | months | 9831 | Yes | Algorithm output | 3 where an interval of 3 months is admissible for residual probing depths of 6 mm or more, i.e. where percent_from6mm_spt is above 3 per cent. Blank where the interval is not admissible |
| from6mm_4months | Integer | 4 | | months | 2058 | Yes | Algorithm output | 4 where an interval of 4 months is admissible for residual probing depths of 6 mm or more, i.e. where percent_from6mm_spt is 3 or less per cent. Blank where the interval is not admissible |
| from6mm_6months | Integer | 6 | | months | 2877 | Yes | Algorithm output | 6 where an interval of 6 months is admissible for residual probing depths of 6 mm or more, i.e. where percent_from6mm_spt is 2 or less per cent. Blank where the interval is not admissible |
| from6mm_12months | Integer | 12 | | months | 4342 | Yes | Algorithm output | 12 where an interval of 12 months is admissible for residual probing depths of 6 mm or more, i.e. where percent_from6mm_spt is 1 or less per cent. Blank where the interval is not admissible |
| max_from4mm | Integer | 3 to 12 | | months | 47 | Yes | Algorithm output | Longest interval admissible on the basis of percent_from4mm_spt |
| max_from5mm | Integer | 3 to 12 | | months | 47 | Yes | Algorithm output | Longest interval admissible on the basis of percent_from5mm_spt |
| max_from6mm | Integer | 3 to 12 | | months | 47 | Yes | Algorithm output | Longest interval admissible on the basis of percent_from6mm_spt |
| algorithm_based_interval_months | Integer | 3 to 12 | | months | 47 | Yes | Algorithm output | Interval computed from the residual probing depth profile at this visit, using the empirically determined stability thresholds of reference [3]. Takes the values 3, 4, 6 or 12 |
| interval_shorter | Integer | 1 | | | 7388 | Yes | Derived | 1 where the actual interval to the next visit was shorter than the algorithm-based interval. Blank otherwise. Compared against algorithm_based_interval_months, not against assigned_spt_interval_months |
| interval_exact | Integer | 1 | | | 9504 | Yes | Derived | 1 where the actual interval matched the algorithm-based interval. Blank otherwise |
| interval_longer | Integer | 1 | | | 6839 | Yes | Derived | 1 where the actual interval was longer than the algorithm-based interval. Blank otherwise |
| consecutive_shorter | Integer | 0 to 37 | | count | None | Yes | Derived | Length of the current run of consecutive visits attended earlier than the algorithm-based interval; 0 where the run is broken |
| consecutive_exact | Integer | 0 to 9 | | count | None | Yes | Derived | Length of the current run of consecutive visits matching the algorithm-based interval |
| consecutive_longer | Integer | 0 to 25 | | count | None | Yes | Derived | Length of the current run of consecutive visits attended later than the algorithm-based interval |
| imputed | Integer | 0 to 1 | | | None | No | Data preparation | 1 where no probing depth measurement existed for this visit in the source records and values were inserted during the original data preparation. Those values have been removed; the probing depth counts and everything derived from them are blank. The number of teeth and the bleeding on probing count were measured and are retained. The inserted values are listed in 04_data_corrections.csv |
| corrected | Integer | 0 to 1 | | | None | No | Data preparation | 1 where a probing depth measurement existed but was judged implausible and replaced during the original data preparation. The replacement is retained here, because it is the value on which the published analyses rest. Both the original and the replacement are listed in 04_data_corrections.csv |
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| File: 04_data_corrections.csv | | | | | | | | |
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| Variable | Type | Range | Categories | Unit | Missing values | Derived | Source | Description |
| pat_id | Integer | 34 to 3661 | | | None | No | Patient records | Patient identifier, unique within the dataset and not linkable to clinical records |
| spt_id | Integer | 1 to 40 | | | None | No | Clinical examination | Sequential number of the supportive periodontal therapy visit within the patient. Unique per patient, not across the dataset |
| correction_type | Categorical | | corrected, imputed | | None | No | Data preparation | imputed = no measurement existed and values were inserted; corrected = a measurement existed and was replaced |
| source | Categorical | | first_visit, next_visit, other, previous_visit | | None | No | Data preparation | Where the value used came from: previous_visit = the values of the preceding visit were carried forward; next_visit = the values of the following visit were used; first_visit = the visit has no predecessor and the origin is not determinable; other = the values match neither neighbouring visit |
| original_n_4mm_spt | Integer | 0 to 81 | | count | 47 | No | Data preparation | Sites with a probing depth of exactly 4 mm, as recorded in the source records before data preparation. Blank where no measurement existed |
| original_n_5mm_spt | Integer | 0 to 60 | | count | 47 | No | Data preparation | Sites with a probing depth of exactly 5 mm, as recorded in the source records before data preparation. Blank where no measurement existed |
| original_n_6mm_spt | Integer | 0 to 25 | | count | 48 | No | Data preparation | Sites with a probing depth of exactly 6 mm, as recorded in the source records before data preparation. Blank where no measurement existed |
| original_n_from7mm_spt | Integer | 0 to 16 | | count | 47 | No | Data preparation | Sites with a probing depth of 7 mm or more, as recorded in the source records before data preparation. Blank where no measurement existed |
| used_n_4mm_spt | Integer | 1 to 47 | | count | None | No | Data preparation | Sites with a probing depth of exactly 4 mm, as used in the published analyses and, for corrected visits, as published in this dataset. Blank where no measurement existed |
| used_n_5mm_spt | Integer | 0 to 30 | | count | None | No | Data preparation | Sites with a probing depth of exactly 5 mm, as used in the published analyses and, for corrected visits, as published in this dataset. Blank where no measurement existed |
| used_n_6mm_spt | Integer | 0 to 18 | | count | None | No | Data preparation | Sites with a probing depth of exactly 6 mm, as used in the published analyses and, for corrected visits, as published in this dataset. Blank where no measurement existed |
| used_n_from7mm_spt | Integer | 0 to 12 | | count | None | No | Data preparation | Sites with a probing depth of 7 mm or more, as used in the published analyses and, for corrected visits, as published in this dataset. Blank where no measurement existed |
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